DESCRIPTION: Osteoarthritis is a highly prevalent and often disabling disorder and its treatment is often frustrating. Most osteoarthritis of the knee affects the medial compartment of the knee which even in an unaffected persons bears 60-70% of loading during walking. With the development of disease in the medial compartment, increased loading of the medial compartment is likely to be one source of localized pain. An operation in which realignment unloads the medial compartment provides excellent pain relief for patients with medial osteoarthritis. One way to lessen load across the medial compartment would be to insert an insole into the shoe that alters the distribution of load in the foot which, in turn, alters load in the knee. Japanese investigators have tested such a wedged insole and have suggested in an uncontrolled study that knee symptoms are improved. No randomized controlled trials of this treatment have been reported but if it is efficacious, it is likely to be safe and inexpensive. The overall objective of this project is to perform a randomized clinical trial of a wedged insole in patients with medial knee osteoarthritis to determine whether the use of these insoles alleviates pain. We will test that hypothesis, that compared to a neutral insert, the provision of a wedged shoe insert alleviates pain in medial knee osteoarthritis. The specific aims are: 1) to undertake a 16-week randomized crossover clinical trial in patients with medial knee osteoarthritis to determine whether prevision of the valgus wedged insert into the shoe leads to lower pain scores during the time of this treatment than during the use of a neutral insert made of the same material and 2) to perform an open label follow-up to track use and effectiveness of inserts. We are recruiting 80-90 patients from clinics at Boston Medical Center and by advertisements in the media, who meet criteria for medial joint osteoarthritis of the knee (roughly 60% of patients with osteoarthritis). Our protocol includes a pre-randomization visit at which time subjects undergo radiographs to evaluate their eligibility and then randomization to either the neutral shoe insert or the wedged insert with a total of six weeks of treatment after which there is a four week washout period followed by six weeks randomized to the other treatment. Our main outcome measure will be the WOMAC, a well validated tool for evaluating knee symptoms and knee related disability. At the end of the study we will be able to test whether provision of a valgus shoe insole relives pain when compared to a prevision of a neutral insole.